We have obtained regularly micro coiled carbon fibers with high reproducibility by the catalytic pyrolysis of acetylene (with impurities) containing a small am ount of sulfur and phosphorus impurities.(S/P).The carbon coils with very small and reg ular coil di ameters (several μm)and coil pitches (>0.7μm )could be obtained with the ma ximum c oil yield of about 20mg/cm 2 substrate and the maximum thickness of coil layer s o f about 8 mm.Carbon coils have generally double helical/spiral structure and may be the ideal candidate for novel subtle energy absorbers,tunable micro devices, bi o activators,Li battery electrodes,absorbers of hydrogen or other gases,etc.In thi s study,we prepared the carbon coils and examined the growth patterns and morpho logies of the carbon coils prepared by different cnditions in detail. It was observed that the coil diameters of the carbon coils and the diameter of the carbon fibers that built up the carbon coils were significantly affected by the reaction temperatures,S/P impurities,and the acetylene flow rate.
